Fun with Numbers

Math puzzle – Can YOU find the area?
Math Queen

In my cave, this qualifies as fun. Looking over the videos on display on YouTube, I noticed this one. It looks like a fun little problem, and it was. When I am tired, usually from not getting enough sleep, I'm looking for some mindless entertainment. One of the games listed in the sidebar are my usual choice, but simple geometric / algebra problems can also amuse me for a few minutes. This one didn't take long, but, as usual, I can't tell you how long because once I started working on it time stopped. Below is a shot of my paper with my work. The answer to the problem (why would you care?) is 2.5 pi.